siur

See also: siúr

Old Irish

siur f (genitive sethar, nominative plural sethir)

Feminine r-stem
	Singular	Dual	Plural
Nominative	siur	siair^L, sieir^L	sethir
Vocative	siur	siair^L, sieir^L	sethra^H
Accusative	siair^N, sieir^N	siair^L, sieir^L	sethra^H
Genitive	sethar	sethar^L	sethar^N
Dative	siair^L, sieir^L	sethraib	sethraib
Initial mutations of a following adjective: ^H = triggers aspiration ^L = triggers lenition ^N = triggers nasalization

Old Irish mutation
Radical	Lenition	Nasalization
siur	phiur, fiur	unchanged
Note: Some of these forms may be hypothetical. Not every possible mutated form of every word actually occurs.

Note: Old Irish s, when from Proto-Celtic *sɸ- and *sw-, was lenited as /f/ (spelled ⟨ph⟩ or ⟨f⟩), rather than the usual /h/ (spelled ⟨ṡ⟩).

Gregory Toner, Sharon Arbuthnot, Máire Ní Mhaonaigh, Marie-Luise Theuerkauf, Dagmar Wodtko, editors (2019), “siur”, in eDIL: Electronic Dictionary of the Irish Language